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Stripe correlations in Na$_{0.75}$CoO$_2$

J. Geck·M. v. Zimmermann·H. Berger·S. V. Borisenko·H. Eschrig·K. Koepernik·M. Knupfer·B. Büchner
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Abstract

We unambiguously demonstrate, based on high-energy x-ray diffraction data and LDA calculations, that sodium-density stripes are formed in Na0.75CoO2 at low temperatures and rule out the previously proposed Na-ordering models. The LDA calculations prove, that the sodium-density stripes lead to a sizeable dip in the density of the Co-states at the Fermi level, pointing to band structure effects as a driving force for the stripe formation. This indicates that the sodium ordering is connected to stripe-like charge correlations within the CoO2 layers, leading to an astonishing similarity between the doped cuprates and the NaxCoO2 compounds.

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J. Geck, M. v. Zimmermann, H. Berger, S. V. Borisenko, H. Eschrig, K. Koepernik, M. Knupfer, B. Büchner. 2005-11-22. Stripe correlations in Na$_{0.75}$CoO$_2$. https://doi.org/10.1103/physrevlett.97.106403

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